Air-brake mechanism.



No. 847,936.- PATENTED MAR. 19, 1907 A. LGOODKNIGHT. AIR BRAKEMECHANISM. APPLICATION FILED NOV. 21. mm I SHEETS-SHEET 1.

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WlIl YLSSbb PATENTED MAR. 19, 1907.

A. L. GOODKNIGHT. AIR BRAKE MECHANISM.

APPLICATION FILED NOV. 21, 1906. I

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AIR-BRAKE MECHANISM.

Specification of Letters Patent.

Patented March 19, 1907.

Application filed November 21, 1906. Serial No: 344.495.

T0 ctZl whom it may concern:

Be it known that I, ALVA L. GOODKNIGHT, a citizen of the United States,residing at Council Bluffs, in the county of Pottawattamie and State ofIowa, have invented a new and useful Air-Brake Mechanism, of which thefollowing is a specification.

This invention relates to air-brake mechanism, and has for its principalobject to imrove the efficiency of the ordinary l/Vestinghouse or NewYork air-brake mechanisms now in use. It is well known that where theordinary equipment is used on a long train it is impossible to secureuniform release of the brakes throughout the whole length of the train,owing to the fact that the pressure in the train-pipe is not evenlydistributed, but is necessarily greater at the head of the train than atthe rear end thereof, and when the engineers brake-valve is moved tofull-release position the current of air sent through the pipe willimmediately release the brakes at the headof the train long before thebrakes at the rear are released, and it frequently happens that trainsbreak in two from this cause. 'Many attempts have been made to secureretarded release, as it is commonly termed, and to maintain somepressure on the brakes at the head of the train while releasing those atthe rear of the train.

One of the principal objects of the present invention is tosecure agraduated release throughout the entire length of the train and toprovide means whereby when full-release pressure is turned on by theengineers brakevalve the brake on the rearmost car of the train Will befully released while the brake on the head car will be only partlyreleased, and the pressure on the brakes at about the center of thelength of the train will be about one-half that on the head-brakes, andso on, the pressure gradually reducing from the head-brakes to the rearbrakes.

A further object of the invention is to provide an improved means forretaining a portion of the pressure in the brake-cylinder in order tosecure retarded release and to providemeans whereby the controllingmechanism shall be automatically moved from pressure-retaining positionto full-release position, the movement being accomplished gradually, sothat the brakes will be gradually released.

A still further object of the invention is to provide a release-valvehaving a port of gradually-decreasing width or area from end to end, sothat as the valve is .moved different distances in response to differentpressures throughout the length of the trainpipe more or less of theeffective area of the valve will be brought into play for the purpose ofsecuring gradual release of the brakes.

A still further object of the invention is to so construct and arrangethe releasing mechanism as to provide for the retention of any desiredamount of pressure in the brakecylinders where trains are descendingheavy mountain grades, provision being made for utilizing an additionalpressure-retaining valve which is placed under the control of the traincrew.

With these and other objects in view, as will more fully hereinafterappear, the invention consists in certain novel features of constructionand arrangement of parts, hereinafter fully described, illustrated inthe accompanying drawings, and particularly pointed out in the appendedclaims, it being understood that various changes in the form,proportions, size, and minor details of the structure may be madewithout departing from the spirit or sacrificing any of the advantagesof the invention.

In the accompanying drawings, Figure 1 is an elevation of a Westinghousetriple valve, showing the application thereto of a releasevalveconstructed in accordance with the invention, the valve being shown innormal or full-release position. big. 2 is a sectional view of the valvemoved to pressure-retaining position. Fig. 3 is a perspective view ofthe valve inverted. Figs; 4 to 11, inclusive, are diagrams showing thedifferent positions to which the valves are moved at different points inthe length of a train.

Similar numerals of reference are em ployed to indicate correspondingparts throughout the several figures of the drawm s.

in carrying out the invention the cappiece, which carries the graduatingstem of the ordinary triple valve 00, is removed and a new cap is placedin position thereon and a new section 5 is bolted on this section,carrying a graduating stem 6 and being provided with a bolting-flange atone end, by which it may be secured to the casing 10 of the deviceforming the subject of the present invention. The end of the section 5is open, so that it may communicate with a cylinder 11, that is formedat one end of said casing 10, and train-pipe pressure entering thesection 5 will act on the main piston of the triple valve in the usualmanner and will also enter the cylinder. At the juncture of the section5 and the cylinder 11 is arranged a gasket 16, forming a seat for apiston 17 when the latter is in normal or full-release position, and thetrain-pipe pressure is constantly exerted against the outer face of thispiston. The opposite end of the casing is connected by a pipe 19 to theauxiliary reservoir, so that the opposite face of the piston 17 will besubjected to auxiliary-reservoir pressure and tending to hold saidpiston in the position shown in Fig. 1.

The lower portion of the casing is "faced to form a valve-seat in whichare arranged three ports 20, 21, and 22, of which the port 22 isconnected to the exhaust-port of the triple valve, while the port 20leads to a pipe 23, in which is arranged a valve 24, the latter beingdisposed usually at the top of the car and being similar to the valvewhich is used ordinarily in connection with the weightedretaining-valve. On level roads the valve is moved to the position shownin Figs. 1 and 2 in order to permit tree passage of the exhaust, andwhere the train is descending heavy grades the valve is turned to closedposition and prevents the escape or air through the pipe 23.

The port 21 leads to a retaining-valve 25, which is preferably oi theweighted type commonly used at the top of the car and usually serves tohold fifteen pounds pressure in the brake-cylinder when the train isdescending a heavy grade. The valve in the present instance, however, isdesigned to be constantly in use, and if the ports 21 and 22 are placedin communication with each other a portion of the air under pressurewill be retained inthe brake-cylinder, and the brakes will be held underlight pressure-usually about fifteen pounds. The lower portion of theretaining-valve casing is in communica tion with the port 20 through apassage 26, in which is arranged a one-way check-valve 28, held to itsseat by a spring 29, that will exert a pressure of approximately fifteenpounds, and when the valve 24 is turned to closed position any air whichmay be allowed to pass to the port 20 from the main port 22 will becompelled to pass the valve 28 and thence pass through theretaining-valve 25,

r and as the valve 28 is held to its seat by a spring exertingapproximately fifteen pounds pressure there will be no possibility ofthe escape of all of the air from the brake-cylinder, such as frequentlyoccurs through the ropking of the ordinary weighted retainingva ve.

Mounted on the valve-seat is a slide-valve 30, that is held down by aleaf-spring 31 of the ordinary construction, and this valve is connectedby a stem 32 to the piston 17. The piston-stem. carries a disk 34,against which bears a spring 35, that tends normally to maintain thevalve and piston in the position shown in Fig. 1, this being the normalrelease position while the train is running. The opposite end of thespring bears against a one-way check-valve 36, that controlscommunication with the auxiliary-reservoir pipe 19, the spring tendingto hold the valve closed and acting to prevent the return ot anyair-pressure from the casing to the auxiliary reservoir.

In the operation of the device, the parts being normally in the positionshown in Fig. 1,the turning of the engineers brake-valve to full-releaseposition. allows air under lull pressure to enter the pipe 18 and forcethe piston 16 to the position shown in Fig. 2, this being accomplishedagainst auxiliaryreservoir pressure which may be within the casing andagainst the resistance otl'ered by the spring. The parts move to theposition shown in Fig. 2, and in this position the air exhaustingthrough the triple valve to pipe 22 will pass through the valve-port tothe port 21 and thence to the retaining-valve; but as the latter is aweighted valve lixed to retain a cxrtain portion 01 the pressure all ofthe air i the hrake-cylinder will not be exhausted; but a sullieientquantity 'say fifteen poundswill be retained in the brake-cylinder torthe purpose ol' holding the head-brake set while recharging andreleasing the rear brakes lllst. \\'hen the engineens brake-valve isturned to lap position, the spring and the auxiliary-rcservoir pressurewill gradually force the piston to the position shown in Fig. 1, and inso doing the exhaust-port 22 will he placed in connnunication with theport 20, which leads to the discharge-pipe 23, and all of the air in thebrakecylinder will be allowed to pass to the atmosphere.

It will be observed that; the spring 3.3 acts to keep the mainpiston-valve in full-release position and at the same time serve toclose the one-way check-valve in the auxiliaryreservoir connection, andas the piston moves toward the position shown in Fig. 2 under train-pipepressure the spring will become more and more compressed and. will exertgradually-increased loree, thus pre-- venting the passage of any airtron] the auxiliary reservoir into the casing.

Under ordinary eireiunstances the valve 24 will be in the open positionshown in Figs. 1 and 2, so that the exhaust which is allowed to pass tothe port 20 may escape freely to the atmosphere; but on heavy grades thevalve 24 is closed and the air passing to the port 20 must first passthe pressurc-ret aining LII lOO

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ing to keep it seated, and this results in the maintenance of twentypounds pressure in the brake-cylinder, this being suflicient to insurethe safety of the train on heavy grades.

The distance to which the valve and piston move is of course determinedby the train-pipe pressure, and as this pressure varies at differentpoints in the length of the train it necessarily follows that the valveat the head of the train will be moved fully over, while the valve atthe rear end of the train vwill be moved to a much smaller extent, thedistance of valve movement gradually decreasing from the head to therear end of the train. Advantage is taken of this fact to secure agradual release throughout the length of the train. This is accomplishedby making the port 40 of the slide-valve of gradually-decreasing width,as shown in Fig. 3, the largest end of the port being opened first andunder the lightest pressure, while as the pressure increases, especiallyat the head of the train, the valve will be moved a greater distance,and the effective port area will be diminished, so that at the head ofthe train the escape of the air is retarded, while at the rear end ofthe train the escape is comparatively free, and at the center of thetrain the retardation is about one-half that at the head of the train.

The position of the valves and the ports on a train of fifty cars isshown in Figs. 4 to 11, inclusive. It will be observed that on the headcar a the exhaust from the port 22 to the port 21, which leads to thepressure-retainmg valve, is approximately the same as that on car I),which may be the sixth or seventh car of the train, while in car 0partial communication will be established through the port 20, and therewill be greater freedom of escape of the air than on cars a and b. Oncar (1, which may be the twenty-fifth or twenty-sixth car of the train,the free exhaust 20 is open to a greater extent, and the available areaof the free exhaust gradually increases throughout cars 6, f, g, and h,the latter car being the last car of the train. In this manner thebrakes are released gradually and the braking pressure graduallyincreases from the head to the rear of the train.

I claim 1. In air-brake mechanism, an auxiliary valve-casing havingports communicating with the triple-valve exhaust, the outer air and apressure-retaining device, and a valve arranged within the casing andmovable under full-release pressure in the train-pipe to place thebrake-cylinder exhaust in communication with the pressure-retainingdevice.

2. In air-brake mechanism, an auxiliary valve-casing havingportsconnected to the triple-valve exhaust, to the outer air, and to apressure-retaining device, and a valve arranged in the casing andcontrolling the port, the valve being movable under full-releasepressure from the train-pipe to place the triple-valve exhaust incommunication with the pressure-retaining device and underauxiliary-reservoir pressure to place the triplevalve exhaust incommunication with the port leading to the outer air.

3. In air-brake mechanism, an auxiliary valve-casing having portsconnected to the triple-valve exhaust, the outer air and to apressure-retaining device, a ported valve arranged within the casing, apiston connected to the valve and exposed on one side to train-pipepressure, and on the other side to auxiliary-reservoir pressure, and aspring acting on the valve and tending to assist the auxiliary-reservoirpressure in moving said valve to free-exhaust position.

4. In air-brake mechanism, an auxiliary valve-casing, a valve arrangedtherein and movable under train-pipe pressure to secure retarded exhaustfrom the brake-cylinder, and under auxiliary-reservoir pressure tosecure free exhaust from the brake-cylinder, and a spring acting toassist movement of the valve to free-exhaust position.

5. In air brake mechanism, an auxiliary valve-casing, a valve arrangedtherein and controlling the exhaust from the triplevalve casing, thecasing being provided with two ports, one leading to the outer air, andthe other to a pressure-retaining device, and the valve being providedwith a port, whereby the brake-cylinder exhaust may be directed throughthe port leading to the outer air or to the pressure-retaining port,orboth, the valve being movable under full release pressure to theretaining or retarding position, and under auxiliary-reservoir pressureto free-exhaust position, and a spring tending to assist the movement tofree-exhaust position, the springs of all of the valves in a train beingcompressed to different extents at different portions of the length ofthe train, thereby graduating the braking pressure from end to endthereof.

6. In air-brake mechanism, a valve controlling the brake-cylinderexhaust, and movable under full-release pressure, and a spring tendingto resist such movement, said valve ICO being provided with a port ofgraduated width or area, and the valves being arranged to assumedifferent positions at ditIerent points in the length of the train inaccordance with variations in train-pipe pressure, whereby the brakingpressure throughout the train may be gradually increased fromfull-release position at the rear of the train toward the head of thetrain.

7. In air-brake mechanism, an auxiliary valve-casing having a portconnected to the triple-valve exhaust and having two escapeports, oneleading to the air and the other to a pressure-retaining device, a valvearranged within the casing and movable under full-release pressure toplace the brake-cylinder exhaust in communication with thepressureretaining device, and a spring tending to resist the movement ofthe valve, said valve having a port tapering in width, so that itseffective area will vary with variations in the train-pipe pressure towhich said valve is responsive.

8. In air-brake mechanism, an auxiliary casing having a port incommunication with the brakecylinder exhaust and two escapeports oneleading to the outer air and the other to a pressure-retaining device, avalve arranged in said casing and controlling the ports, a pistonconnected to the valve and exposed onone side to train-pipe pressure,and on the opposite side .to auxiliary-reservoir pressure, a check-valvecontrolling communication between the auxiliary reservoir and thecasing, and a spring arranged between the two valves.

9. In air-brake mechanism the comblnation wlth an auxlhar T valve-casinhavin b b ported communicatlon with the brake-cylinder exhaust andprovided with two ports, one leadin to the outer air a nessure-retamin b7 t) valve with which the second port communicates, a valve arranged inthe port which. leads to the outer air, said valve being adjustable toopen or close the port, 'a springpresscd check-valve by which said portsmay be placed in communication with each. other, a piston arrangedwithin the casing and exposed on one side to train-pipe pressure, and.

on the other side to auxiliaryreservoir pressure, a valve controllingthe ports, and a spring tending to assist the movement of the valveunder auxiliary-reservoir pressure.

10. In air-brake mechanism, an auxiliary valve-casing, a valve arrangedtherein and movable under train-pipe pressure to secure retarded exhaustfrom the brahe-eylimler and under auxiliary-reservoir pressure to securel'rce exhaust from the brahe-cylinder, and springs exerting variableforce at dill'erent points in the length of the train for assistingmovement oi the valve to free-exhaust position.

11. In air-brake mechanism, an auxiliary valve-casing having a portconnected to the exhaust-port of the triple valve and provided with twoports, one of which leads to the retainingantlve and the other to avalved discharge, the valved discharge being in communication with saidretaming-valve, an auxiliary retaining-valve arranged in the connection,a slide -.valve controlling the ports, said slide-valve being exposed onone side to train-pipe pressure, and on. the opposite side toauxiliary-reservoir pressure.

In testimony that I claim the foregoin as my own I have hereto allixedmy signature in the presence of two witnesses.

ALVA L. G OODIIN lGl ll.

itnesses:

E. Home TALBERT Jxo. E. PARKER.

